WAWUZAT Northstar build thread (lots of pix) (Page 10/16)
WAWUZAT AUG 24, 05:55 PM
That crossover pipe on the original Caddy may have measured 2.25" at the round ends, but it was flattened severely where it snakes down and up between the engine and transaxle. That flattend area might have been closer to the equivalent of a 1.5" diameter tube.
WAWUZAT AUG 29, 08:25 PM
Spent a couple days cutting and fitting the elbow sections to the main manifold tube. Then cut openings in the tube itself once the elbow sections were saddled on the tube and their outline could be traced. The plasma-arc machine was very handy for this work. Without it, I would've had to do all the cutting with abrasive cutting wheels since I cannot use my oxy-acetylene torch to cut stainless steel. Here's a shot taken before I tackwelded it this evening.

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"For those who understand, no explanation is necessary. For those who do not, no explanation is possible."

ryan.hess AUG 29, 09:21 PM

quote
Originally posted by WAWUZAT:

That crossover pipe on the original Caddy may have measured 2.25" at the round ends, but it was flattened severely where it snakes down and up between the engine and transaxle. That flattend area might have been closer to the equivalent of a 1.5" diameter tube.



I cut one apart, and they did a good job at keeping the area constant and equivalent to 2.25" round tubing. That's not to say it didn't flow like a 2" diameter tube.....
WAWUZAT AUG 29, 09:31 PM

quote
Originally posted by ryan.hess: I cut one apart, and they did a good job at keeping the area constant and equivalent to 2.25" round tubing. That's not to say it didn't flow like a 2" diameter tube.....



You cut one up? Interesting! The one aspect of that cross-over tube that boggled my mind was where it was routed on the Caddy. There must have been a lot of heat transferred to the oil pan, bellhousing, and other parts of the transaxle.

[This message has been edited by WAWUZAT (edited 08-29-2007).]

ryan.hess AUG 29, 10:28 PM
actually the crossover tube is insulated quite well (it's double walled with fiberglass in between)

You're right though, there would be a LOT of heat transfered into the oil pan if it weren't insulated. Possibly a fire hazard if you have any leaks.

[This message has been edited by ryan.hess (edited 08-29-2007).]

jstricker AUG 29, 10:30 PM
Ryan,

On the rear side, it's 2.25" out of the manifold but on the front side it's less than 2". I'm planning on using the stock rear manifold on both sides, the going to, well, YOU know what.....



John Stricker

quote
Originally posted by ryan.hess:

The stock exhaust is 2.25" (going by the stock crossover diameter). I think 2", even with our shorter exhaust, might be a bit on the restrictive side.



WAWUZAT SEP 01, 06:48 PM
Spent a few evenings this past week & Saturday to layout & cut the main conical tubes where the elbows "saddle" onto them. Finished welding the elbows to those tubes today, and tacked them to the manifold flange. Here's a couple photos taken when test-fitting the manifolds on the engine.

Left head / forward side ...


Right head / aft side ...

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"For those who understand, no explanation is necessary. For those who do not, no explanation is possible."

WAWUZAT SEP 14, 05:12 PM
I've learned that I do not like MIG welding stainless steel too much. That stuff draws up / shrinks a lot. After I finished welding the stainless manifolds to the carbon steel flanges, they both warped a bit. The warpage wasn't there when I made my first pass on the outside, but they curved slightly when I welded the inside diameters. Before anyone asks, I used Type 308 wire for stainless-to-stainless joints, and Type 309 wire for stainless-to-steel. The steel flanges are 3/8" thick.

I clamped the two manifolds together to where they were flat again, then tackwelded them so I could remove the clamps. Then I heated them with a torch to relieve weld-induced stress. I couldn't get the entire flange red hot at one time, only a portion at a time. Still, it didn't work. They sprung apart when I cut the welds loose. So, my machinist buddy is going to get a little job from me to mill the gasket surfaces flat again.

Weather permitting, I'll start cutting my rear strut towers this weekend to make some extra room for the Northstar. I'll post more pix then.
WAWUZAT SEP 19, 09:02 PM
I got sidelined again. I'm getting to the point where I now only hope to get the engine into the car with all the mounts fabricated by the end of the year. Maybe get some more exhaust system work done, too. Then it will have to sit again while I build more suspension parts for Ford Excursions. Folks are sending me all sorts of requests for items for which I've run out of stock, and they're even offering extra $$$ if I'll make those parts before 2008. Last Sunday was lost to getting my Harley ready for pick-up by the winning eBay bidder. Then I spent a few days this week to find and buy a replacement bike. Bought a used '06 Honda ST1300 in Norfolk yesterday. This coming weekend is lost to a wedding I must attend at Ft. Belvoir near DC.

But I did get a little bit done last Saturday. I layed-out cutting lines parallel to the section of chassis immediately below the rear strut towers. Then I cut the towers and removed the old torque-strut bracket. This was done so I can fit some flat 16ga. sheet steel and gain some room in the engine compartment around the Northstar. After these panels are welded in, I'll cut out the front trunk bulkhead, and fab/fit a replacement panel after the engine is in place. Here's a shot of the lay-out work ... after marking the chassis with a scribe, I applied some masking tape so it would be easy to see while using the abrasive cutting wheel ...


And here's a shot taken after cutting the strut tower and removing the bracket ...


The driver side was also cut in the same manner. I now need to make cardboard templates for laying out the sheet steel for cutting and fitting.
fieroguru SEP 19, 09:28 PM

quote
Originally posted by WAWUZAT:







That is taking the lowering of the fiero chassis to the extreme! Good job on the build!